Avoid 100% inspection and maintenance accidents

Avoid 100% inspection and maintenance accidents

Oct 01, 2019

Can Lockout tagout avoid nearly 100% inspection and maintenance accidents? yes

Data from the U.S. bureau of labor statistics show that 80 percent of equipment repair injuries are caused by failure to shut down the device, 10 percent by someone else starting the device, 5 percent by failure to control potential energy, and the other 5 percent are mostly caused by shutting down the energy source without confirming whether the shutdown is actually effective.

Case study:

February 16, 2005, a refinery liquefied gas workshop 1500 tons/year sulfur recovery device exhaust flue burned through, emergency shutdown treatment. At about 6:20 PM on February 19, a migrant worker from the construction unit entered the furnace and removed the retaining wall in the middle of the furnace leading to the e-101 direction of the primary condenser. The workshop technician then put on a jumpsuit, a lighting torch and a filter (anti-hydrogen sulfide) gas mask and went into the furnace for inspection. About 5 minutes later, the monitor found no movement in the furnace, immediately went into the furnace to rescue the technician, rushed to the hospital, but failed to save, died.

The direct cause of the accident: because the two-stage mixing valve connected with the inlet pipeline of the two-stage conversion reactor was in a semi-open state, nitrogen was poured into the top of the sulfur generator from the entrance of the two-stage conversion reactor through the two-stage mixing valve, and died of nitrogen suffocation when the party concerned entered the furnace for deep inspection.

Indirect causes of the accident: the workshop did not assign a special person to be responsible for blind plate plugging, did not establish a blind plate plugging registration form, and did not block the secondary mixing valve connecting the sulfur making furnace top with the inlet pipeline of the secondary conversion reactor. This hidden trouble was not found in the subsequent test and inspection. This is a major cause of the accident.

Therefore, in a sense, a good LOTO can avoid nearly 100% of inspection and maintenance accidents.